Oil well screen



Sept. 20, 1932.

J. P. WHANN OIL WELL SCREEN Filed March 25. 1929 a portion of the bar winding of such screen being shown in section so as to disclose the perforations in the pipe forming the core of such screen.

Fig. 2 is a cross-section taken substantially as indicated by the line 22 of Fig. 1.

Fig. 3 is an enlarged fragmentary section through that portion of the screen indicated 7 by the line 33 of Fig.- 1, this sectional view being conventional in that. it represents drainage openings not occurring on the line '3-3 defining the position of the sectionrelative to Fig. 1. V

Fig. 4 is an enlarged perspective view looking upwardly at a trussed lug formed in a screen bar, as indicated by the arrow 4 of Fig. 5 is a fragmentary detail illustrating the preferred method of forming the bridged lugs in a bar which is to be wound on a perforated pipe, such figure having the purpose of explaining the general characteristics of theform of lug shown in the preceeding figuresby disclosingthe method of forming suchlugs.

Fig. 6 is a diagrammatic perspective view showing Ttheform of flat spacing lug'which i is formed in a bar by the use of a tool having substantially sharp corners extending perpendicularlyto the face or edge of the bar in which such tool fonnsa'bridg'e or lug.

by flaring or enlarging them at their outer ends in such a manner that, as shown in Fig. 5, each hole will communicate with several of the drainage channels or screen inlet slots 13 formed between consecutive turns of a bar or bars 14 on the exterior of theperforated' pipe 10. At the upper end of the pipe 10 I have shown thestandard form of'coupling 15 and have further indicated in Fig. 1, circumferential and longitudinal welds 16 and 17 by which the bar 14 is secured to the coupling 15 and held in properly spaced position on the pipe 10.

In Figs. 1 to 5, the wire 14 is shown spaced apart by'therepeated use of atrussed lug member 20, which lug 20 consists of a flat web of metal 21, and downwardly curved side webs 22, as best shown in Fig. 4, projecting laterally from the side of the bar 14, with the upper surface 23 of the central web portion 21 of the lug '20 in substantiallythe same plane as the upper face 24 of the bar 14. The side webs 22 are of triangular form,

.dition is not necessary to practise thereby serving as trusses or brackets of a character to co-operate with and reinforce the central web portion 21, giving the entire lug21maximum physical strength relative to the amount of metal employed therein. In

the preferred form of the invention, the outer surface of the bar 14 and the outer surface of the lug 2O lie in the same plane, but this conof the invention in its alternative forms; I

'The lug 20 shown in Fig. 4 projects laterally .from the extreme upper portion of the side wall 25 of the bar 14 and a depression or pocket 26 is formed in the side of face 25 in position immediately underneath the lug 20. As will-be seenin Fig. 3,the lugs 20 occupy a space at the upper portion of the drainage channels 13, this resulting in a reduction of the height of the channels at the positions of the lugs. The area which a lug 20 occupies in the cross-section or a drainage channel 13 is in a measure compensated for by the depression or pocket in the side of the bar 14 beneath the lug 20. Whereas the height of the drainage channel 13 is decreased by the presence of the lug under which fluid must flow in the drainage channel in seeking lnlet into the pipe 10 through an opening 11,

the area of cross-section of the channel 13 is maintained nearly constant by the widening of the channel where it passes under a lug 20, as the result of the lateral enlargement of the channel under each lug.

In Figs. 5 and 7, I illustrate my preferred method of making the trussed form of lugs and the channel enlarging depressionsin the screen bar. 30 indicates a wheel or roller member having aplurality of rectangularprism tool bits 31 and 32 projecting therefrom in radial, equally spaced position, the

lugging 'wheel 30 may be considered to rotate in the direction of the arrow 33, with the bar 14 at the same time moving in the direction of the arrow 34.

The tools 31 and 32, etc., are so positioned that they will engage the under face 35, Fig.

4,'of the bar 14, being suficiently offset rela-- tive to an edge of the bar 14 thatwhen the tool. indicated at 31 moves into the position of the tool 32, metal will be displaced from the side portion of the bar 14 adjacent to and 'includin g the face 25, this metal being forced upwardlytoward the face 24 of the bar. 14 and at the same time expanding laterally and being flanged outwardly and compressedbe tween an, anvil roller 37 and the outer'end face 38 of the tool bit, as indicated at Fig.5.

By rounding off the corners 39 of the tool bits indicated'at'31 and32', these corners being the outer corners of the tool bit which project perpendicularly or laterally relative to the face 250 f the b-ar14, it is possible to produce as part of thelug 20 the side, triangularly shaped, webs 22 -which haveftheespecial utility of reinforcing the lug structure by reason of the fact that inthis manner the entire lug is arched in a direction parallelor in alignment with thelengthof the bar 14. I i

In Fig. 6 I indicate a lugging tool 40 hav ing a substantially fiat end face 41, a cutting edge 42, and perpendicularly or laterally extending corners 43, which corners 43 are maintained substantially sharp,i-nstead of being rounded off in the manner of the corners 39 shown in Fig. 5. When this tool 1s employed to punch a lug in a bar such gas 44, by forcing the tool upwardly relative to the bar, a tongue-like lug 45 is formed, containing substantially all of the metal d1splaced from the area occupied bythe depression or pocket 46. In this operation of lug construction therehas been no dragging back of the metal at the edges of the lug in such a manner as to form, the truss webs 22, but

' instead of being provided with such webs the sides 47 of the lug are left cleanly defined as shown. A distinct advantage in this form of lug is that the obstruction of the drainage channelor screen slot due to the presence of the lug in the upper part thereof, is kept at a minimum. a

In Fig. 5 the neutral axis AA of the bar 14 is indicated. When this bar 118 bent into curved form such as would be necessary in winding it on the p1pe'10, the portion of the bar above the axis A A elongates and the portion below the axis AA shortens. Naturally the elongation and compression of the upper and lower portions of the bar produce strains in the bar in addition to the tension placed on the bar during the winding process for the purpose of holding the bar tightly to the pipe. As I have previously mentioned, it has been customary in the lugging of wire for use on a screen of this character, to force 7 a chisel-shaped tool down into the upper face 24 of the wire or bar such as indicated at 14, nearthe edge thereof, so that the action of the chisel will produce a forcing out of breaking either during the winding operation or at some time after the wire-has been wound inplace on the pipe, as'during the placing of thescreen in a well. The breakage of ,WIIQ at such time is often disastrous,ow1ng to the fact that the projecting end of the wire will catch on some obstruction in the well, causing a portion of the winding of the screen to be displaced or pulled from the perforated pipe forming the tubular core of the screen. In

my presentinventionl usea bar or large wire having a lug formed in the upper edge there 7 offrom metal taken from the original body of the bar, but this lug in no way detracting from thetensional strength of the outer portion of the bar which must meet the strains of elongation-during the winding of, the bar on the pipe. The lug, projecting as I- have described, from the upper portion of the bar has an accompanying feature consisting of the result of the presence of the lug projectbar.

. I claim as my invention: I f 1. A well screen of the character described,

including: a perforate tubular member; and

a bar wound on said tubular member, said bar having substantially continuous side walls bridge lugs projecting from the upper porturns of the bar apart, there being depressions in. the side wall of said bar under said lugs the drepression or pocket in the bar under the V lug,whereby to compensate for the reduction in height of the drainage channel between two consecutive turns of a bar on the pipe as V 8 ing laterally from the upper portion ofthe T extending approximately "radially with respect to the axis of said tubular member and '9 I jtionsof said bar for holding the separate v of substantially the same length as-said lugs. i

2. A well screen of the character described,

including: a perforate tubular member; and I a bar wound on said tubular member, said I bar having substantially continuous side walls extending approximately radially with respect to the axis of said tubular member and bridge lugs projectingfrom the upper portions of said bar for holding the'separate 4 turns of the'bar apart, there being depresits sions in the side wall of said bar under said lugs of substantially the same length as said lugs, and reinforcing webs extending down. from thesides of said lugs to engagement. with the side wallof said bar adjacent to V the. respective ends of saiddepressions.

I 3. A well screen bar for winding on a tubular frame, comprising a'rod having an inner substantially flat face adapted to rest against said frame and an outer face opposite to said inner face, there being side faces connecting the edges of said inner and i outer faces, said bar having a lug projecting laterally from one of said side faces and V i a depression under said lug of substantially the same lengthas said lug. I

4. A well screen bar forwinding on a tu; bular frame, comprising a'rod having an iriagainst said frame and an outer face opposite to said inner face, there being side faces connecting the edges of said inner and outer faces, said bar having a lug projecting laterally from one of said side faces and a depression under said lug of substantially .ner substantially flat face adapted to restvv the same length as saidlug', and feinforcing I Webs extending down. from the sidesrof said lug to engagement with the side face of said bar adjacent to the respective ends of said depression. V a A Signed at Los, Angeles, in the county of Losi Angeles and State of California, this 20th day of March, 1929.

JESSE P. WHANN.

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